Join us on THEO’s blog for our monthly series on the evolving landscape of welding, where history, tradition, and innovation intersect. This month, we're honored to have Joe Dallarosa starting this series by offering his insights into the historical depths of welding. It's an invitation to journey with us through the transformative world of welding.
The process of joining metals, welding, existed far before imagery of hooded welders creating bright arcs. Welding is an ancient technology continuously being improved. Utilizing heat and pressure ancient civilizations were able to build jewelry boxes, weapons, and dining utensils. The process of welding allows for more complicated, larger, and more intricate parts to be made.
The bronze age is the earliest known era of welding. Egyptians as early as 4000 BCE were welding copper. Later, welding materials like iron, bronze, gold, and silver. An example, using charcoal to heat iron ore into sponge iron, Egyptians then hammered the iron pieces into a singular piece. This process is known as pressure welding. Egyptians utilized other techniques like soldering metals together using lower-temperature alloys to bond two different pieces. These techniques form the backbone for ancient metalwork with gradual improvements continuing to the medieval ages.
The iconic blacksmiths emerged in the medieval era as forge welding appeared. Forge welding is an extension of earlier techniques, requiring a blacksmith to heat the metals to join and then hammer them together. In the 16th century, the word weld was first referenced in manuscripts and Vannoccio Biringuccio, an Italian metallurgist published the first printed books on metallurgy. Blacksmiths were central to crafting tools and weapons throughout the medieval era. A vital component of advancing technologies reliant on the craft.
In the early 1800s, modern ideas of welding began to appear with the discovery of the arc using two carbon electrodes and a battery. After stabilizing the arc, it could be used to melt and join metals. Further, acetylene was discovered in 1836 leading to more advancements in welding such as electric generators, gas welding, and cutting, and improved stability in arc welding. Advancements in metallurgy continued with the creation of blast furnaces and the discovery of oxygen.
The 20th century brought another revolution to welding. Thermite welding allows the welding of large pieces through the chemical reaction of a metal powder and metal oxide that burns at temperatures exceeding 2200 C. The advancements persisted as alternate current welding was invented by C.J. Holslag offering more control and efficiency over arc welding of the time. The demand for welding greatly increased during the world wars as more and more components required welding for assembly.
Modern techniques have exploded with improvements to arc welding like shielded metal and gas metal arc welding. Both utilize a shield gas to prevent oxidation. Shielded metal uses a flux-coated electrode that emits a gas as the flux is burned. Gas metal utilizes a wire electrode and shield gas deployed through a separate tank. TIG welding, tungsten inert gas, is similar in process but uses a non-consumable tungsten electrode and inert gases to shield it from oxidation. The process has greatly improved arc welding from its initial conception. Currently, laser welding has taken center stage, providing precise controls at high speeds with minimal distortions to welded materials. Welding will continue to advance and be a crucial part of manufacturing increasingly complicated and larger systems.
